Oat fiber attenuates circulating oxysterols levels and hepatic inflammation via targeting TLR4 signal pathway in LDL receptor knockout mice

Abstract

Oxidized forms of cholesterol, oxysterols which involved in lipid homeostasis and inflammatory reaction, played a vital role in the formation of atherosclerotic lesion. The present study aimed to explore how oat fiber affected circulating oxysterols and targeted hepatic inflammation in LDLR−/− mice. Animals were given a high-fat/cholesterol (HFC) diet without or with 0.8% oat fiber for 14 weeks. Oat fiber decreased serum LDL-c level, accompanying by a reduction of hepatic lipid accumulation and atherosclerotic lesion. The increment of circulating oxysterols, including 7-HC, 25-HC, 27-HC and 6a-Hydroxy-5a-cholestanol caused by a HFC diet in LDLR−/− mice, were inhibited by oat fiber feeding. Notably, oat fiber blocked TLR4 signal pathway via downregulating the downstream adaptor MyD88 and activating NF-kB p65 signal. In summary, the present study provided experimental evidence that oat fiber feeding retarded the progression of atherosclerosis via acting on circulating oxysterols and ameliorating hepatic inflammatory reaction by targeting TLR4/MyD88/NF-κB signal pathway.